This invention relates to animal traps and more particularly this invention relates to a low impact leghold type animal trap.
Leghold traps have been in use for many years in the fur trapping industry and are wide spread in their application. Depending on the size of the trap, a great variety of animals can be caught, usually without damage to the fur. These traps have recently been widely criticized because of certain aspects which are considered by some people to be inhumane. One of the most important of the disadvantages leading to the charges of inhumanity is the fact that when the jaws clamp shut on the leg of the animal, they do so with considerable force and inflict severe pain.
Interestingly, the basic design of the leghold trap has not changed over the years with new improvements being made generally in the trigger assembly or other components not affecting the operating principle of the trap. See, for example, U.S. Pat. Nos. 833,827, dated Oct. 23, 1906; 1,356,775 dated Oct. 26, 1920; 1,939,190, dated Dec. 12, 1933; and 3,335,517, dated Aug. 15, 1967.
Although there have been improvements to leghold traps over the years, the basic construction remains the same today as it was 100 years ago. Specifically, a pair of jaws pivotally mounted on a base plate are moved upwardly from the set position to the sprung position by spring means urging the jaws together. As already mentioned, it has been found that the impact force of the jaws coming together is extremely high and, in fact, unnecessarily high. In order to prove this, a technique was developed at the Laboratories of Arthur D. Little, Inc. for measuring the forces involved in these traps and a measuring apparatus was constructed.
It will be recognized that the behavior of a trap cannot be expressed as a single number. As the trap closes, the geometry varies continuously and the impact force, therefore, varies according to the size of the object between the jaws. Similarly, the clamping force after impact varies with jaw opening. Plotting the force versus the jaw opening accurately defines a trap. As will be discussed more fully hereinbelow, if means could be provided to lessen the impact forces and provide more uniform clamping force at smaller openings of the trap, the standard leghold trap can be made more humane.
Accordingly, it is a primary object of the present invention to provide a leghold type trap which operates in a more humane manner than the prior art traps.
It is another object of the present invention to provide a leghold type trap wherein the clamping force of the jaws is materially reduced at smaller openings.
It is yet another object of the present invention to provide a leghold type trap wherein the impact force of the jaws is reduced.